Processes for the manufacture of fibrils by orienting thin streams of polymer solutions and precipitating the polymer therefrom are known in the art. See U.S. Pat. Nos. 2,988,782; 2,999,788; and 4,013,751. All of the processes known in the art are deficient in one or more respects. Certain of the processes precipitate the solute polymer before it is fully oriented and, as a consequence, the fibrils do not develop their ultimate potential strength. Other of the processes have a high capital cost or low productivity, or both. The literature reported processes also are subject to the shortcoming that few if any variations can be made in the zone in which the polymer is being precipitated. As a consequence, few if any modifications can be made in the physical properties of the fibrils being produced.
There is a need in the art for an improved fibril manufacturing process which will (1) provide fibrils of high strength, (2) have low manufacturing costs, and (3) have the capability of significantly modifying the physical properties of the fibrils being produced in the process.